/*******************************************************************************
 * Copyright (c) 2000, 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.ui;

/**
 * An editor is a visual component within a workbench page. It is
 * typically used to edit or browse a document or input object. The input 
 * is identified using an <code>IEditorInput</code>.  Modifications made 
 * in an editor part follow an open-save-close lifecycle model (in contrast 
 * to a view part, where modifications are saved to the workbench 
 * immediately).
 * <p>
 * An editor is document or input-centric.  Each editor has an input, and only
 * one editor can exist for each editor input within a page.  This policy has 
 * been designed to simplify part management.  
 * </p><p>
 * An editor should be used in place of a view whenever more than one instance
 * of a document type can exist.
 * </p><p>
 * This interface may be implemented directly.  For convenience, a base
 * implementation is defined in <code>EditorPart</code>.
 * </p>
 * <p>
 * An editor part is added to the workbench in two stages:
 * <ol>
 * 	<li>An editor extension is contributed to the workbench registry. This
 *    extension defines the extension id, extension class, and the file 
 *    extensions which are supported by the editor.</li>
 *  <li>An editor part based upon the extension is created and added to the
 *    workbench when the user opens a file with one of the supported file
 *    extensions (or some other suitable form of editor input).</li>
 * </ol>
 * </p>
 * <p>
 * All editor parts implement the <code>IAdaptable</code> interface; extensions
 * are managed by the platform's adapter manager.
 * </p>
 *
 * @see org.eclipse.ui.IWorkbenchPage#openEditor(IEditorInput, String)
 * @see org.eclipse.ui.part.EditorPart
 * @since 1.0
 */
public interface IEditorPart extends IWorkbenchPart, ISaveablePart {

    /**
     * The property id for <code>isDirty</code>.
     */
    public static final int PROP_DIRTY = IWorkbenchPartConstants.PROP_DIRTY;

    /**
     * The property id for <code>getEditorInput</code>.
     */
    public static final int PROP_INPUT = IWorkbenchPartConstants.PROP_INPUT;

    /**
     * Returns the input for this editor.  If this value changes the part must 
     * fire a property listener event with <code>PROP_INPUT</code>.
     *
     * @return the editor input
     */
    public IEditorInput getEditorInput();

    /**
     * Returns the site for this editor. 
     * This method is equivalent to <code>(IEditorSite) getSite()</code>.
     * <p>  
     * The site can be <code>null</code> while the editor is being initialized. 
     * After the initialization is complete, this value must be non-<code>null</code>
     * for the remainder of the editor's life cycle.
     * </p>
     * 
     * @return the editor site; this value may be <code>null</code> if the editor
     *         has not yet been initialized
     */
    public IEditorSite getEditorSite();

    /**
     * Initializes this editor with the given editor site and input.
     * <p>
     * This method is automatically called shortly after the part is instantiated.
     * It marks the start of the part's lifecycle. The 
     * {@link IWorkbenchPart#dispose IWorkbenchPart.dispose} method will be called 
     * automically at the end of the lifecycle. Clients must not call this method.
     * </p><p>
     * Implementors of this method must examine the editor input object type to
     * determine if it is understood.  If not, the implementor must throw
     * a <code>PartInitException</code>
     * </p>
     * @param site the editor site
     * @param input the editor input
     * @exception PartInitException if this editor was not initialized successfully
     */
    public void init(IEditorSite site, IEditorInput input)
            throws PartInitException;
}
